Abrasive wheel dressing tools



Dec. '1, 1953 H. G. TEATHER 2,660,994

ABRASIVE WHEEL DRESSING TOOLS Filed May 16, 1951 INVENTOR. HAfiRY'Gw/m: 72A THE/F ATTORNEY Patented Dec. 1, 1953 ABRASIVE WHEEL DRESSING TOOLS Harry George Teather, London, England, assignor to Precision Diamond Products Ltd., London,

England, a corporation of Great Britain Application May 16, 1951, Serial No. 226,555

1. This invention relates to abrasive wheel dressing tools and more particularly to a dressing tool comprisinga headadapted to be attached to a fixture adjacent the surface'of the Wheel to bedressed, the head being formed to adjustablysupport a diamond tipped nib inclined at an angle to the wheel surface.

In the precision grinding and polishing of variou metal parts, the abrading wheel must be periodically dressed to true the same to precision accuracy and sharpen the abrading surface thereof. The carbon, boart or ballas (commonly referred to as an industrial diamond) which provides the dressing point for the nib, will obviously Wear and develop a flat after continued dressing action. In order that a sharp diamond point or edge is at all times presented for contact with the surface ,being dressed, it is necessary. to periodically rotate or index the nib through a predetermined angle to present a, fresh point which has become symmetrically sharpened in previous dressing operations.

Indexing of the nib has, heretofor been accomplished, as shown in Jearums British Patent No. 556,675, by calibrating the tool to indicate a series of equally spaced stations around the nib to which the nib may be indexed in sequence to present a fresh diamond edge or point in working position. Indexing may be effected by rotating the nib toalternate stations 50 that the indexing distance is double the distance between consecutive stations. By this indexing procedure, a diamond point. would be presented at each station when the nib had been rotated through two revolutions.

However, in such indexing, there is constant 'risk that the operator will inadvertently adjust the nib to an intermediate station, and as a con-' sequence wear the diamond without useful resuit and produce a poorly and inaccurately dressed Wheel surface.

An object of this invention is to provide animproved dressing tool constructed to facilitate the properindexing of the nib through a sequence of equally spaced stations in alternating order and in a foolproof manner to thereby ensure maximum useful life to the diamond and th dressing of the wheel surface in minimum time to precision accuracy and maximum sharpness.

Other objects and advantages of this invention will become apparent as the disclosure proceeds.

Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself, and the manner in which it may be carried out, may be better under- 6 Claims. (Cl. 125-41) A 2 stood byreferring to the following description taken in connection while the accompanying drawing, in which Fig. I is a plan view of this improved abrasive wheel dressing tool as it would appear when supported by a fixture and in dressing contact with an'abrasive wheel v Fig. II is a longitudinal cross section of the dressing tool as viewed in the plane of line II-II of Fig. III;

Fig. III is an end elevational view of the dressing tool;

Fig. IV is a transverse cross section of the dressing tool as viewed in the plane of line IV-IV of Fig. II;

Fig. V is another transverse cross section of the dressing tool as viewed in the plane of line vv of Fig. 11;

Fig, VI is a fragmentary transverse cross section of the dressing tool as viewed in the plane of line VIVI of Fig. II; and

Fig. VII is a plan view of the Allen key used in assembling, adjusting and indexing the dressing tool. 1 Similarreference characters refer to similar parts throughout the several views of the drawing and the specification.

Referring to the drawing, this improved abrasive wheel dressing tool comprises a head I 0 fixed to a shank l3 designed to be mounted in a suitable fixture Fto adjustably support a removable diamond tipped nib 30 at an inclined angle to the surface of the abrasive wheel W to be dressed. The supportingfixture F may be constructed to reciprocate the tool nib transversely across the operating surface of the Wheel during the dressing operation.

Th head lflmay be mad in a single piece from east or shaped metal and presents a solid body section II. The supporting shank I2 may have a threaded end portion I-3 extending into a threaded cavity M in the body section II and firmly but removably secured thereto by a set screw l5 threaded into the body section II. The set screw may have a polygonal Wrench socket cavity in the end thereof so that it may be manipulated by the polygonal. end portion a of the Allen key as shown in-Fig. VII.

The head Ill also presents a nib-containing section 16 having a tubular bore to receiveand support the nib 30 on a longitudinal axis ex:- tending at an inclined angle of approximately 30 to the longitudinal axis of the supporting shank I 2. The nib-containing section l6 presents a main bore ll of cylindrical form which 3 terminates at an internal collar portion l8 as shown in Fig. II. The internal collar portion It presents a reduced bore l9 which leads into an enlarged open bore cavity 22 of cylindrical form. The internal collar portion It thus defines an inner shoulder 23 and an outer shoulder 2|. The main bore ll, the reduced bore l9 and the open base cavity 22 are in axialv alignment. As shown in Figs. III and IV, the open bore cavity 22 also defines a semi-cylindrical side wall portion 23 whose free edge is notched out to present an entry notch 2i and an exit, notch. 2.5 spaced by a raised cam edge 26 whose purposewill be hereafter explained.

The tool head It is also provided with a square or polygonal-shaped clamp receiving'hole flex:-

tending through the body section II as shown.

in Figs. II V. The hole 21 presents one face 28 thereof in intersecting relation to themain bore I? to define a common rectangular shaped opening 28 therebetween.

Thecutting diamond supportingnib 3fl-.may be shaped from a steel rod to present amain body portion 3i of cylindrical form: designed to. snugly seat within the main bore ll of the tool head. The cutting diamond 3 2 is solidly set in the end face 35 of the main body portion of. the nib by a selected metal matrix 33. The

exposed end face 34 is preferably tapered at an angle of 30 to 45 to adequately expose the cutting: tip: of the diamond 32 asset therein.

The nib 3E3 presents a reduced body portion 35 extending from the main body portion. 3lto define an inset shoulder 36 and iscylindrically shaped to snugly telescope into the reduced bore [9 ofthe internal collar portion iii of the head.

The nib 39 terminates in a threaded end portion 31 of reduced diameter to present a. second .inset shoulder 38- at the point of juncture with the reduced body portion 35. The-threaded end portion 31 of the nib is designed to extend through the open. bore cavity 22. of the tool head. The threaded end portion 3?, the reduced body portion 35 and the main body portion 3| of the nib are axially aligned and as assembled in the head are in axial alignment, with themain bore H, the reduced bore IS! and the; open bore cavity 22 of the tool head;

Thenib 38 is removably and adiustablylocked within the bore of the nib-containing section lfiofthe head by-a nib lock 40 which. comprises ahead clamp pad 4i connected to a foot clamp pad. 42 by a socket screw 43 as shown in Figs. II and V. The clamp pads 41 and 42 have'the same polygonal shape as the receiving h'ole z'l and are sized to snugly telescope therein. The

socket screw .3 has a head portion i linset'within a conforming cavity in the head clamp pad 4| and is equipped with a; polygonal wrench socketfor manipulation by the polygonal end a'. of the Allen key A. The screw 43.has a threaded'shank portion 45 threading into the footpad 42.. Both clamp pads 4i and llpresent inclined nib clamping faces positionedat the, rectangular opening 29 to engage the nib. body portion. 31. By tightening the screw 43, the. clamp pads 4| and 42 will grip and'hold the nib 30 in adjusted. position, and by loosening the screw 43 the nib 3!] may be rotated in the bore of the tool head as presently described. The screw 4.4 presents a circumferential groove 4'] to receive spaced indentations or dimples 48, punched into the body of the clamp pad. 4| after assembly onthe screw head 44, so that the clamp pad 4! may be withdrawn from the hole 21 with the socket screw 43.

An index disc made of metal and designed to snugly fit within the bore cavity 22 of the tool head, is provided with a threaded hole 5! to be threaded onto the threaded end portion 31 of the nib to serve as a nib supporting nut. The index disc 50 is also designed to snugly seat on the outer shoulder 2-! of the internal collar portion [8 of the tool head. A series of equally spaced key receiving holes 52 extend radially around the periphery of the index disc 50 and are shaped to receive the cylindrical end a of the Allen key A. The index disc 58 as shown in. Fig. IV is equipped with seven equally spaced socket holes 52: to provide for seven indexing stations. The. index disc 58 is capped by a domeshaped locknut 53 having an internal threaded socket" 54 for attachment to the threaded end portion 3'! of the nib. The locknut 53 may be provided withdiametrically spaced flattened outer. faces. 55 for wrench application. When the locknut 53. has. been tightened, the index disc to will seat against the secondary inset shoulder 38 or thenib.

The tapered diamond supporting end of the nib as mounted in the tool head normally projects from the nib-containing section. [6 thereof to fully expose the cutting diamond for wheel dressing application.- A. helical spring. 56 is contained within the main bore l! of thetool head as shown in Fig. II to normally retain the indexing disc seated against the outer shoulder 21 of the. internal collar portion. [8. of the head. The helical spring 56 is preferably frusto-conical in shape and embraces the reduced body portion 35 or" the nib, with its reduced end 51 seating against the primary inset shoulder 35 of the nib. The larger end, 58 of. the helical spring 56 isdesigned to seat against a split ring or circlip 63 formed as shown inFigs. II. and VI. The circlip 83 is made of spring steel and istempered to tightly fit within the main bore l! of the tool head andseat against the adjacent inner shoul der 20 thereof. The endsfi l of the circlip 63 are normally spaced apart, but may be drawn together when inserting and removing. the circlip into and from the bore llby. the provision of grip holes 65. therein to. which. long-nosed. pliers may be. applied.

A; retaining pin extends through a conforming holeextending through the internal collar portion l8 and presents. a head portion 62 which seats under. the. circlip 63.. The retaining pin is designed for vertical movement within the. collar hole provided therefor and presents a tapered end portion 61 normally exposed at the surface of the outer. shoulder. 2i... The tapered end Lportiontl' of the retaining pin Bil is designed to selectively nest within. pin.sockets= 59 formed in the'adjacent face of indexing disc 58. Each of the pin sockets 59 is positioned directly adjacent and below eachof'the socket holes 52 in the index disc 50 as indicated in Fig. IV, and are arranged to. cooperate with the springloaded pin 60 to retain the index. disc. 50 andthe nib .30 in the selected" indexed position.

As thus constructed and assembled, the helical spring 56 operates tov maintainv theindex disc 59 resiliently seated against the outer shoulder 21 of the tool. heacl,.leaving the operating end of the nib. exposedfor dressing application to the abrasive wheel. When. the point. of the diamond 3.2 hasbeen worn down. and flattened by wheel diiessingaction, the nib.3ll is rotated. through a Allen key, the nib 3G maythen be turned to the right as shown in Fig. III by pulling the Allen key over the raised cam' edge 26, causing a corre-'- sponding telescoping movement of the nib 30 in the bore of the head. against the action of the helical spring 56. When the disc turning Allen key reaches the exit notch 25 of the tool head, the helical spring 56 will telescope the nib in'the opposite direction to its normal operating position, and the index 50 will again seat against the outer shoulder 2| of the head and there be retained by the spring loaded pin 60. When the second cutting point of the diamond nib is thereafter worn by wheel dressing action so that it no longer dresses with the desired efficiency, a third diamond point may be presented for wheel contact by repeating the adjustmentabove described.

This improved abrasive wheel dressing tool as illustrated inthe accompanying drawing presents seven dressing stations, which may be designated as stations I to 1 inclusive as defined by the seven equally'spaced peripheral socket holes 52 in the disc 50. However, as shown in Fig. III, only two alternate socket holes 52 are exposed at the entry notch 24 and the exit notch 25 of the tool head, the intermediate socket hole being covered by the intervening raised cam edge 2510f the head. The exit notch 25 in the head is so shaped that the index disc cannot be turned when the Allen key is at the exitfnotch. Thus, the nib can only be rotated by inserting the Allen key A at the entry notch 24. and then turningthe key to the right as shown in Figs. III and IV to the alternate station. When seven operating stations are provided, each to present a fresh diamond point for dressing action, the sequence of station adjustment would be from station I to 3, then from station 3 to 5, then from station 5 to 1, then from station I to 2, then from station 2 to 4, and finally from station 4 to 6. Thus the nib would be adjustable to seven alternate stations and would make two complete revolutions during the useful life of the diamond.

It will be appreciated, however, that a five station or a seven station or a nine station adjustment of the nib may be provided as desired, by forming a corresponding number of equally spaced key sockets 52 in the index disc 59, and by locating the key entry notch 24, exit notch 25 and intermediate cam edge 26 to accord.

When the diamond set in the nib has been worn after several indexing adjustments until its useful life has been substantially consumed, the nib may be readily removed from the head by loosening the socket screw 43 and then removing the dome-shaped locknut 53 and index disc 50 from the threaded end portion 31 of the nib, thereby permitting complete withdrawal of the nib from the tool head. The used diamond can then be reset or a new cutting diamond bonded to the operating end of the nib.

The indexing features of this improved abrasive wheel dressing tool ensures maximum life to the cutting diamond mounted in the nib thereof, with a sharp diamond point precisely presented for wheel dressing action. This improved, wheel dressing tool is substantially foolproof inuse, and is'constructed to ensure indexing adjustment of the nib for maximum dressing eificiency without calculated attention or inspection by the operator to determine whether the best diamond point is. being presented for wheel dressing action. Thus a fresh sharp point, generated between two flats worn in the previous cycle, is constantly presented .to the abrasive wheel without calculated attention, thereby ensuringmaximum useful life of the diamond and rapid dressing of the abrasive Wheel to maximum sharpness and precision accuracy.

It is understood that this invention may be embodied'in various modifications and adaptations and is not limited to the particular embodiments described and illustrated, but that various revisions, substitutions and changes may be made by those skilled in the art.

' What is claimed is: I

.1. An improved abrasive wheel dressing tool including in combination, a tool hea'd'having.-.a nib receiving bore, a mounting nib having a body portion telescoping within the bore of the tool head, clamping means set within the tool head for adjustably securing the nib body in the bore of the tool head, an index disc secured to the nib body having a series of equally spaced indexing stations indicated thereon,.said-tool head having 'a wall contoured to present a pair of spaced notches designed to expose two alternate indexing stations insaid index disc and conceal the remaining indexing'stations therein.

2. An improved abrasive wheel dressing tool including in combination, a tool head having a nib receiving bore, a mounting nib having a body portion telescoping within thebore of the tool head, clamping means setwithi'n the tool head for adjustably securing. the nib body in'the bore of the toolrhead, an index disc secured to the nib body, said index disc having a series of equally spaced indexing sockets each defining an indexing station, said tool head having a wall contoured to present a pair of spaced notches designed to expose two alternate indexing sockets in said index disc and to cover the remaining indexing sockets therein against accessibility except by alternate indexing adjustment of the nib.

3. An improved abrasive wheel dressing tool including in combination, a tool head having a supporting shank and a nib receiving bore whose longitudinal axis is inclined at an angle to the axis of the shank, a mounting nib having a body portion telescoping within the bore of the tool head, clamping means set within the tool head for adjustably securing the nib body therein, an index disc secured to the nib body, said index disc having a series of equally spaced indexing sockets extending around the periphery thereof, said tool head having a wall contoured to present a key entry notch and a key exit notch designed to expose alternate indexing sockets in said index disc to key access and prevent access to the remaining indexing sockets therein except by alternate indexing adjustment of said nib.

4. An improved abrasive wheel dressing tool including in combination, a tool head having a nib receiving bore, a mounting nib having a body portion telescoping within the bore of the tool head, adjustable clamping means set within the tool head for securing the nib body in the bore of the tool head, said bore having a shoulder defined therein, an index disc removably secured to said nib body having indexing sockets equally spaced oi the. tool head, said bore around. theperiphery thereof, resilient means within the bored the head operativezto'z'normally retain saidv index disc seated againstsaid shoulder,- said head havinga wall portionsurrounding theperiphery of said index disc contoured to present a key entry notchand a key exit notchdesigned to expose a pair of alternate indexing sockets in said index disc, said. wall presenting a' key camming edge extending between said paired indexing sockets closing the: intermediate indexing socket to key. access.v

5. An improved abrasive wheel dressingntool including in combination, a tool head having a nib receiving bore, a mounting nib having abody portion telescoping: Within the bore of? the tool head, adjustable clamping. means set. within: the tool. head for securing the. nib body in: the bore having'an internal collar presenting inner and outer shoulders; an index disc having indexing socketsequally spaced around the periphery thereof, means'for removabl'y securing said index disc to the nib body, a helical spring. contained within the bore of the head seating between an abutment shoulder formed on the nib body and the inner shoulder of said internal collar and operative to normally retain. said index disc seated against the outer shoulder of said internal collar; said head havin a wall surrounding the periphery of saidindex disc contoured to present a key entry notch and akey exit notch exposing a pair of alternate indexing sockets in said index disc, said wall presenting atraised key camming edge extending between said paired notches closing the intermediate and' adjacent indexing socket to key access.

6; An improved Iabrasive: wheel dressing'tool including. in combination, a tool head having a supporting shank and a nib, receiving bore whose longitudinal axis is inclined. at an: angle. to: the axis of the shank; a mounting nib having a body portion telescoping. within the bore. of the; tool head, adjustable clamping means set within the tool head for? securing the nib body in the; bore of the tool'head, saidbore-having' aninternal collarpresenting inner; and. outer. shoulders,- an index disc and a locknut threaded to one: end of the nib body; said index disc having indexing sockets: equally spaced around the periphery thereof, a helical spring, contained within the bore of the head embracing a, body section of the nib and seating between an abutment shoulder formed on the nib body and the inner shoulder of said internal collar, a lock pin extending through said internal collar operative to fix the indexed position of .saididisc; said helical spring being operative to normally retain said. index disc seated against the outer shoulder of said internal collar, said head'having awall portion surrounding the periphery of said index disc and contoured'to' present a-key entry notch and a key exitnotch which expose a pair of alternate indexing sockets in said index disc; to key access; said wall portion presenting a raised key camrning' edge extending 'between said paired notches andclosing the intermediate and adjacent indexing'so'cket to key access.

HARRY GEORGE TEATHER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 160,484 Terry Mar. 2, 1875 764,466 Henry July 5, 1904 1,122,539 Rose Dec, 29, 1914 1,178,687 Strickland Apr. 11, 1916 1,400,614 Lovejoy Dec. 20, 1921 2,400,368 Palmer May 14, 1946 2,505,684 McClernon Apr. 25, 1950 2,535,670 Croft Dec. 26, 1950 FOREIGN PATENTS Number Country Date 556,675- Great Britain Oct. 15, 1943 

